445 research outputs found

    The Magnetocaloric Properties of Gd5Si4 Alloy Prepared by the New Method

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    We report on a new method for preparation the magnetocaloric alloy Gd5Si4. By mechanical alloying under argonatmosphere and then melting sample by arc furnace, we produced the Gd5Si4 alloy. The structure and magnetothermalproperties of the alloy have been investigated with the help of powder X-ray diffraction and magnetization measurements.This compound crystallized in the orthorhombic structure with space group pnma. In X-ray powder diffraction pattern, aminor orthorhombic GdSi2 phase was observed as a second phase. For this compound, the second order phase transitionwas observed. The maximum isothermal magnetic entropy change of the Gd5Si4 compound at 348K was found to be -10J/(kg K) in an applied field of 0.5T

    Effect of Metacognitive Skills Training on Metacognitive Awareness, Self-Efficacy and Academic Achievement of University Students

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    Aims: Metacognition deals with active monitoring and adjusting the results and cognitive processes to gain the purpose. Academic self-efficacy is dependent on students’ perception of learning and is an important factor in the success of students reasoning. This study aimed to determine the effectiveness of metacognitive skills training on metacognitive awareness, self-efficacy and academic achievement in university students. Materials & Methods: This semi-experimental study with a pretest-posttest controlled approach was conducted in all students of Kashan University of Medical Sciences in 2014. 50 participants were selected by cluster sampling and were randomly divided into 2 intervention and control groups. Metacognitive awareness of reading strategies inventory (MARSI) and General Self-efficacy Scale were used for data gathering. Data were analyzed using ANCOVA test. Findings: There were significant difference between the score of the pretest and posttest of the intervention group in both self-efficacy and metacognition awareness. In addition, there were significant differences between posttest scores of intervention and control groups in self-efficacy (p<0.001; F=42.46) and cognitive awareness (p<0.001; F=190.99), but there was no significant difference (p=0.072; F=3.39) in academic achievement between the intervention and control groups’ posttest scores. Conclusion: Metacognitive training affects metacognitive awareness and self-efficacy but it is not founded for academic achievement

    Estimation of the Thyroid Secondary Cancer Risk on the Patient of Standard Breast External Beam Radiotherapy

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    Background: The purpose of this study was to estimate the secondary cancer risk of thyroid in standard radiotherapy methods which are commonly used for breast cancer patients. Methods: A total of 64 breast cancer patients (their age range was around 50 years old) who referred to Seyed-Al-Shohada hospital (Isfahan, Iran) were included in this study. The radiotherapy of the mentioned patients was performed using 6-MV photon beams. Dose measurements were also done using thermoluminescent dosimeters. Calculation of the risk of developing secondary cancer in thyroid was done using the Biological Effects of Ionizing Radiation Committee VII and recommended quantity of the International Radiation Protection Commission, excess relative risk. Results: The mean radiation dose to thyroid for the tangential beams, tangential field with supraclavicular (SC) field, and also a tangential field with SC field in modified radical mastectomy (MRM) were 0.883 ± 0.472, 1.512 ± 0.365, and 1.587 ± 0.37, respectively. The risk of developing secondary thyroid cancer over a period of 5 years after breast cancer therapy in the tangential, tangential with a SC field, and also tangential beam with SC field in MRM were 9.974 ± 4.318, 17.891 ± 0.365, and 18.783 ± 4.384, respectively. The mean of the measured thyroid doses in patients treated with tangent fields was significantly lower than the patients under the irradiation of the tangent fields with SC field (P < 0.001). Conclusions: Using radiation protection equipment is suggested for breast cancer patients who treated with the studied radiotherapy methods

    Improved battery life for context awareness application in smart-phones

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    The new smart-phones with new operating system and portable sensors support the basis for context awareness systems and applications for handling user activity and user privacy. Nowadays, individuals need new services and real time information anywhere and anytime. Context awareness is an emerging service, which could be able to improve the user experiences in current situation. Context awareness can be considered as location, calendar, user activity and etc. The review of the literature proves that context awareness in mobile phone can be useful and studied as unavoidable service in next generation of smart-phone applications. In this paper, a short review about context awareness in mobile phone is studied, furthermore, we critically analyzed related works of context awareness in smart-phones. The review shows that the most important context in mobile phone is location, which is mostly obtained by using Global Positioning System (GPS) sensor in mobile phones but GPS can significantly increases battery consumption in mobile phones. In this regard, a framework as Improved Battery life in Context Awareness System (IBCS) is proposed to improve battery life and reduce cost of using GPS in context awareness applications based on smart-phones. The review argues the weakness and strength of these studies, and aims to (a) indicate the most important context in mobile phone, (b) reduce the battery consumption of GPS sensor in mobile phone

    The effect of lavender essential oil and nanoemulsion on Trichomonas vaginalis in vitro

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    Background: Trichomonas vaginalis is the cause of trichomoniasis. Due to increased resistance and side effects of the drugs, the aim of this study was to assess an anti-trichomonias effect of lavender (Lavandula officinalis) essential oil and nanoemulsion on T. vaginalis in vitro. Materials and Methods: Lavender essential oil components were characterized by gas chromatography. To determine the cytotoxicity effects, the macrophage cell line J774.A.1 was used. Trichomonas vaginalis was isolated from vaginal secretions of the infected women and then cultured in the TYM complete medium and passaged for 10 days. The effect of essential oil and 1 lavender nanoemulsion in concentrations 10, 25, 50 and 100 &mu;g/mL in the 24-well plate were examined at 1, 2 and 3 hours as triplicate. Positive control was metronidazole (50 &mu;g/mL). The number of live and dead parasites was counted by trypan blue stain with a Neubauer slide. Results: The viability of the macrophages for lavender essential oil was 93.70 and for nanoemulsion was 90.90. Essential oil and nanoemulsion of lavender in concentration of 100 &mu;g/mL and during 3 hours showed 81.7 and 81.9 growth inhibitory, respectively. This difference was not statistically significant. Conclusion: Lavender essential oil and nanoemulsion has a desirable inhibitory effect on growth of T.vaginalis and can be a good choice for conducting therapeutic investigations regarding trichomonial infections

    Precipitation and flow behavior of AISI 630 stainless steel deformed at elevated temperatures

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    Hot compression tests were performed on the samples of AISI 630 stainless steel in the temperature range of 900-1050 C and at strain rates of 10–3- 1 s21. Single peak stress flow behavior was observed at all deformation conditions. An irregular relationship was found between the peak point of flow curves and processing condition, i.e., temperature and strain rate. The stress relaxation tests at the temperature range of 900-1050 C revealed that dynamic precipitation (DP) of carbides in the matrix and grain boundaries causes the considered irregularities in the peak stres

    Human platelet antigen 1-6, 9 and 15 in the Iranian population: An anthropological genetic analysis

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    Human platelet antigens (HPAs) are membranous glycoproteins considered as alloantigens due to their polymorphisms. HPA-incompatibility in multiple pregnancies or blood transfusion can induce the development of alloantibodies leading to thrombocytopenia. The frequency of HPAs varies among populations, so that deep knowledge of HPA frequencies will help us to reduce those incompatibilities. Herein, we studied the allele and genotype frequencies of HPA1-6, HPA9, and HPA15 among the Iranians with intra- and inter-populations analyses on 36 worldwide populations with diverse ethnicities. The analysis shows that the HPA2 and HPA5 have the greatest differences in genotype distribution between the Iranians and other nations, although similar to other populations, the sole allele found in HPA4, 6, and 9 is �a�. Despite other HPAs, the most frequent allele in HPA15 is �b�, which is also abundant in HPA3. Hierarchical clustering indicates the highest degree of global similarity in HPA genotype frequency among Iranian, Argentinian, Brazilian, and German Turkish populations. Our findings can be applied to decrease the risk of alloimmunizations and platelet disorders, especially in neonates. © 2020, The Author(s)
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